In many applications of electrical generator systems, load demand relative to generator power capacity is often low. However, in most generator systems, the engine/generator must be run even when only a small load is present.
Another problem with many electrical generator systems is that the speed of the internal combustion engine has to be operated at a constant high speed to provide power even though only a small electrical load is present. Thus, a substantially constant level of noise is created regardless of the load present.
In many applications, such as recreational vehicle (RV) applications or commercial mobile vehicles, storage batteries in conjunction with DC (direct current) to AC (alternating current) inverter circuitry are often used to provide "silent" power during periods of time when little or no noise is desired. However, the storage batteries can only be used for a limited period of time without any charging. After use of the storage batteries for a limited period of time, the engine/generator has to be run to provide the AC power which often creates an undesired level of noise.
While storage batteries can provide power for a limited period of time during low load demands, storage batteries typically do not supply sufficient power for high load demands, such as air conditioners (A/C) or a clothes washing machine, etc. Thus it is necessary to run the engine/generator to meet the relatively high load demands of these appliances. In addition, even for a small load, the storage batteries can only be used for a limited period of time as discussed above.
Engineers have designed so-called load management systems which control power distribution to various loads by varying the speed of the engine/generator set. When a new load is added into a power supply bus line, the load management system senses the additional load and requires more power from the engine/generator. In addition to other problems, one problem with these systems is that the engine at the reduced speed might not have the power to satisfy new load demands and unacceptable low voltage excursions be experienced.
Moreover, despite the fact that the speed of the generator set is varied, the engine/generator set is operated even when extremely low loads are present. Moreover, the engine/generator set typically has a top end speed which limits the electrical load it can support.
The present invention solves these and other problems associated with existing systems.